Apparatus and method for image capture using image stored in camera

ABSTRACT

An apparatus for capturing an image using an image stored in a camera includes a lens system for optically receiving an image, an image signal processor for converting the received image into a preview image and generating a first-resolution image using the received image at predetermined periods, a first buffer for receiving the first-resolution image from the image signal processor and temporarily storing the received first-resolution image, a display for displaying the preview image received from the image signal processor and the first-resolution image received from the first buffer, and a controller for controlling the image signal processor to display the first-resolution image temporarily stored in the first buffer on the display upon receiving an image capturing signal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to capturing a still image usingimages stored separately at predetermined times in addition to a previewimage and, more particularly, to an apparatus and method for storinghigh-resolution images received at predetermined times in a first bufferand capturing a still image using the high-resolution images stored inthe first buffer.

2. Description of the Related Art

An ordinary digital camera includes a lens system for forming an imageof a subject on a film or a surface of an image sensor, and the imagesensor for detecting the image formed by the lens system as anelectrical signal. The film or the surface of the image sensorcorresponds to an image surface of the lens system. A focus of the lenssystem varies in position according to a distance between the lens andthe subject. Therefore, it is possible to capture or photograph imagesof various qualities according to changes in the position of the imagesurface, which is associated with a position of the subject.

A user photographs a desired subject in an image using a digital camerawith the above-stated elements. In order to more easily take a pictureof a desired subject, the user may use a preview image that provides animage of the subject in real time, to previously get hold of the imageto be captured. The preview image is displayed on a display through thelens system in real time, and the user may easily take a picture of thedesired subject while viewing the displayed preview image. A camera withthe function of outputting a preview image on the display is thenecessaries of life, playing an important role in multimediacommunication required in the modern society.

An internal structure of a common camera outputting a preview image willbe described with reference to FIG. 1 below.

FIG. 1 shows an internal structure of a conventional camera outputting apreview image. Elements of the camera include a lens system 101, animage sensor 103, a driver 111, an Image Signal Processor (ISP) 105, adisplay 107, and a controller 109.

Referring to FIG. 1, the lens system 101 optically receives an image ofa subject, and includes at least one lens. The image sensor 103 convertsthe image of a subject optically received by the lens system 101 into anelectrical signal. The ISP 105 processes the electrical signal receivedfrom the image sensor 103 on a frame-by-frame basis, and outputs alow-resolution image frame that is converted according to screenfeatures (size, picture quality, resolution, etc.) of the display 107.

The display 107 displays the low-resolution image frame received fromthe ISP 105 on a screen, and the driver 111 moves the lens system 101according to control of the controller 109. Although not shown in thedrawing, the driver 111 includes a motor for providing a driving force,and a carrier for moving the lens system 101 forward and backward by thedriving force. The controller 109 controls the driver 111 to move thelens system 101 to a focal position.

Now, a description will be made of a procedure for receiving andanalyzing a preview image using the elements in FIG. 1.

When an image of a subject is optically received through the lens system101, the image sensor 103 converts the optically received image of asubject into an electrical signal and provides the electrical signal tothe ISP 105. The image of a subject received through the lens system 101is continuously received in real time, and the image sensor 103 convertsthe received real-time image of a subject into an electrical signal, andprovides the electrical signal to the ISP 105. The ISP 105 converts thereceived real-time image of a subject into a low-resolution previewimage and displays the low-resolution preview image on the display 107.The user may monitor the received real-time preview image on the display107.

Commonly, however, when a user captures an image while viewing a previewimage, an image following the preview image is captured. If the subjectis stationary, it doesn't matter even though an image is captured afterthe time the user intends to take a picture of the subject. However, incase of an image sensitive to motion, an unwanted image may be capturedafter the time the user intends to take a picture.

SUMMARY OF THE INVENTION

An aspect of the present invention provides an apparatus and method forreading an image stored in a first buffer as a captured image anddisplaying the captured image on a display, when a user inputs an imagecapturing signal independently of a preview image being displayed on thedisplay.

In accordance with one aspect of the present invention, there isprovided a method for capturing an image using an image stored in acamera. The method includes receiving an image and converting thereceived image into a preview image; generating a first-resolution imageat predetermined periods and temporarily storing the first-resolutionimage in a first buffer; determining whether an image capturing signalis received; and if the image capturing signal is received, storing thefirst-resolution image temporarily stored in the first buffer in aseparate storage space and displaying the first-resolution image on adisplay.

In accordance with one aspect of the present invention, there isprovided an apparatus for capturing an image using an image stored in acamera. The apparatus includes a lens system for optically receiving animage, an image signal processor for converting the received image intoa preview image and generating a first-resolution image using thereceived image at predetermined periods, a first buffer for receivingthe first-resolution image from the image signal processor andtemporarily storing the received first-resolution image, a display fordisplaying the preview image received from the image signal processorand the first-resolution image received from the first buffer, and acontroller for controlling the image signal processor to display thefirst-resolution image temporarily stored in the first buffer on thedisplay upon receiving an image capturing signal.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and advantages of certainexemplary embodiments of the present invention will be more apparentfrom the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a diagram showing an internal structure of a conventionalcamera outputting a preview image;

FIG. 2 is a diagram showing an internal structure of a camera using animage stored in a buffer according to an embodiment of the presentinvention;

FIG. 3 is a diagram showing an internal structure of a camera usingimages stored in a plurality of buffers according to an embodiment ofthe present invention;

FIGS. 4A and 4B are diagrams showing a process of taking a picture usinga subject's image stored in a buffer according to an embodiment of thepresent invention;

FIG. 5 is a diagram showing a process of extracting a high-resolutionimage from among images received at different times according to anembodiment of the present invention; and

FIG. 6 is a flowchart showing a process of taking a picture using animage stored in a buffer according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of thepresent invention with reference to the accompanying drawings. The termsand words used in the following description and claims are not limitedto the bibliographical meanings, but, are merely used by the inventor toenable a clear and consistent understanding of the invention.Accordingly, it should be apparent to those skilled in the art that thefollowing description of exemplary embodiments of the present inventionare provided for illustration purpose only and not for the purpose oflimiting the invention as defined by the appended claims and theirequivalents.

FIG. 2 shows an internal structure of a camera using an image stored ina buffer according to an embodiment of the present invention. The camerashown in FIG. 2 includes a lens system 201, an image sensor 203, anImage Signal Processor (ISP) 205, a display 207, a first buffer 209, amemory 211, a controller 213, a key input unit 215, and a driver 217.

Referring to FIG. 2, the lens system 201 optically receives an image ofa subject, and includes at least one lens. The image sensor 203 convertsthe image of a subject optically received by the lens system 201 into anelectrical signal. The ISP 205 processes the electrical signal receivedfrom the image sensor 203 on a frame-by-frame basis, and outputs apreview image that is converted into a low-resolution image according toscreen features (size, picture quality, resolution, etc.) of the display207. The ISP 205 generates high-resolution images at predeterminedperiods and provides the high-resolution images to the first buffer 209.That is, the ISP 205 generates an image corresponding to a predeterminedperiod among received images, as a high-resolution image, andtemporarily stores the high-resolution image in the first buffer 209.The low-resolution preview image displayed on the display 207 in realtime and the high-resolution image stored in the first buffer 209 mayvary in size, picture quality and resolution according to user settings.

The display 207 displays a preview image received from the ISP 205. Ifthere is an instruction of the controller 213, the display 207 displaysthe high-resolution image temporarily stored in the first buffer 209instead of displaying the converted image received from the ISP 205. Ifthere are one or more high-resolution images, they may be displayed on ascreen of the display 207 together or selectively.

The first buffer 209 temporarily stores the high-resolution imagereceived from the ISP 205, and may store one or more high-resolutionimages according to user settings or a size of a storage space. Thefirst buffer 209 provides the temporarily stored one or morehigh-resolution images to the memory 211 according to an instruction ofthe controller 213. The memory 211 stores one or more high-resolutionimages received from the first buffer 209.

The controller 213 controls the ISP 205, the first buffer 209, and thedriver 217. If an image capturing signal is received, the controller 213provides a converted-image output interrupt signal to the ISP 205, andprovides the first buffer 209 with a signal for outputting one or morehigh-resolution images temporarily stored in the first buffer 209 to thedisplay 207. Upon receiving such a signal, the first buffer 209 providesthe temporarily stored one or more high-resolution images to the memory211 and stores therein. The temporarily stored one or morehigh-resolution images may be stored all in the memory 211, or may beselectively stored in the memory 211 according to user selection. One ormore high-resolution images stored in the first buffer 209 may bedisplayed on the display 207 without conversion, but one or morehigh-resolution images may be delivered back to the ISP 205 and thendisplayed after they are converted into low-resolution images accordingto screen features of the display 207.

The key input unit 215 provides an image capturing signal to thecontroller 213 through an input means such as a button, and the driver217 moves the lens system 201 according to control of the controller213. Although not shown in the drawing, the key input unit 215 mayinclude a motor for providing a driving force, and a carrier for movingthe lens system 201 forward and backward by the driving force.

The ISP 205 may include a first converter (not shown) for converting thereceived image into a preview image, and a second converter (not shown)for generating image data from the received image at predeterminedperiods.

The memory 211 is a nonvolatile memory, and may be an external memory.

FIG. 3 shows an internal structure of a camera using images stored in aplurality of buffers according to an embodiment of the presentinvention. The internal structure of the camera shown in FIG. 3 furtherincludes a second buffer 219 in addition to the elements of the camerashown in FIG. 2.

Referring to FIG. 3, the lens system 201 optically receives an image ofa subject, and includes at least one lens. The image sensor 203 convertsthe image of a subject optically received by the lens system 201 into anelectrical signal. The ISP 205 processes the electrical signal receivedfrom the image sensor 203 on a frame-by-frame basis, and outputs apreview image that is converted into a low-resolution image according toscreen features (size, picture quality, resolution, etc.) of the display207. The ISP 205 generates high-resolution images at predeterminedperiods and provides the high-resolution images to the first buffer 209.That is, the ISP 205 generates an image corresponding to a predeterminedperiod among received images, as a high-resolution image, andtemporarily stores the high-resolution image in the first buffer 209.The low-resolution preview image displayed on the display 207 in realtime and the high-resolution image stored in the first buffer 209 mayvary in size, picture quality and resolution according to user settings.

The display 207 displays the preview image received from the ISP 205. Ifthere is an instruction of the controller 213, the display 207 displaysthe high-resolution image temporarily stored in the first buffer 209instead of displaying the converted image received from the ISP 205. Ifthere are one or more high-resolution images, they may be displayed onthe display 207 together or selectively.

The first buffer 209 temporarily stores the high-resolution imagereceived from the ISP 205, and provides the temporarily storedhigh-resolution image to the memory 211 according to an instruction ofthe controller 213. The memory 211 stores the high-resolution imagereceived from the first buffer 209. If a new high-resolution image isstored in the first buffer 209, the second buffer 219 stores ahigh-resolution image generated in the next period. If a high-resolutionimage is stored in the second buffer 219, the high-resolution imagestored in the first buffer 209 is deleted. Thereafter, a high-resolutionimage generated in the next period is stored in the first buffer 209. Ifthe high-resolution image is stored in the first buffer 209, thehigh-resolution image stored in the second buffer 219 is deleted. Thatis, if a new high-resolution image is received and temporarily stored,each of the first buffer 209 and the second buffer 219 delivers ordeletes the high-resolution image stored in the opposite buffer.

The controller 213 controls the ISP 205, the first buffer 209 and thedriver 217. If an image capturing signal is received, the controller 213provides a converted-image output interrupt signal to the ISP 205, andprovides the first buffer 209 with a signal for outputting one or morehigh-resolution images temporarily stored in the first buffer 209 to thedisplay 207. Upon receiving such a signal, the first buffer 209 deliversthe temporarily stored one or more high-resolution images to the memory211 and stores therein. The temporarily stored one or morehigh-resolution images may be stored all in the memory 211, or may beselectively stored in the memory 211 according to user selection. One ormore high-resolution images stored in the first buffer 209 may bedisplayed on the display 207 without conversion, but one or morehigh-resolution images may be delivered back to the ISP 205 and thedisplayed after they are converted into low-resolution images accordingto screen features of the display 207.

The key input unit 215 provides an image capturing signal to thecontroller 213 through an input means such as a button, and the driver217 moves the lens system 201 according to control of the controller213. Although not shown in the drawing, the key input unit 215 mayinclude a motor for providing a driving force, and a carrier for movingthe lens system 201 forward and backward by the driving force.

While the number of buffers is limited to two in the drawing, the numberof buffers may increase according to user settings.

A process of capturing an image of a subject using the elements of thecameras shown in FIGS. 2 and 3 will be described below.

FIGS. 4A and 4B show a process of taking a picture using a subject'simage stored in a first buffer according to an embodiment of the presentinvention.

FIG. 4A shows a scene where a preview image is received, in which apreview image corresponding to an image of a subject is output on thedisplay 207 in real time using the lens system 201 of the camera. Sincethe preview image output on the display 207 is not a high-resolutionimage desired by the user, a low-resolution image converted according toscreen features (size, picture quality, resolution, etc.) of the display207 is output. Meanwhile, while the preview image is being output on thedisplay 207, high-resolution images are generated and temporarily storedin the first buffer 209 at predetermined periods. The temporarily storedhigh-resolution images may vary in picture quality and size according touser settings, and the number of the temporarily stored high-resolutionimages may be subject to change according to a size of a storage spacein the first buffer 209 where the high-resolution images are temporarilystored.

In the case where two buffers are provided as shown in FIG. 3, thesecond buffer 219 deletes the previously stored high-resolution image ifa new high-resolution image is stored in the first buffer 209.Thereafter, if a high-resolution image generated in the next period isstored in the second buffer 219, the first buffer 209 deletes thepreviously stored high-resolution image.

FIG. 4B shows a result after an image capturing signal is input by aninput means such as a button. If an image capturing signal is receivedfrom the user, the controller 213 provides a converted-preview imageoutput interrupt signal to the ISP 205. Upon receiving the interruptsignal, the ISP 205 no longer delivers the converted preview image tothe display 207. After that, the controller 213 provides the firstbuffer 209 with a control signal for outputting one or morehigh-resolution images temporarily stored in the first buffer 209 on thedisplay 207. Upon receiving this signal, the first buffer 209 stores oneor more images displayed on the display 207 in the memory 211, anddisplays the temporarily stored one or more high-resolution images onthe display 207.

The controller 213 may select a user-desired image from among the one ormore high-resolution images displayed on the display 207 before storingone or more images displayed on the display 207 in the memory 211according to user settings, and may store only the selected image in thememory 211. Although not shown in the drawing, the controller 213 maydirectly display one or more high-resolution images stored in the firstbuffer 209 on the display 207 without conversion, or may display one ormore high-resolution images after delivering the high-resolution imagesto the ISP 205 and converting them into low-resolution images accordingto screen features of the display 207.

FIG. 5 shows a process of extracting a high-resolution image from amongimages received in different periods according to an embodiment of thepresent invention. It is assumed in FIG. 5 that an image of a subject isreceived through the lens system 201 of the camera once every 0.1second.

Referring to FIG. 5, one or more images 501 to 509 are sequentiallyreceived through the lens system 201 of the camera. The received one ormore images 501 to 509 are all sequentially converted intolow-resolution preview images according to screen features of thedisplay 207 in the ISP 205 and then displayed on the display 207.

The ISP 205 generates high-resolution images at predetermined periods,and stores them in the first buffer 209. That is, an image 503 receivedat 0.2 second and an image 507 received at the ISP 205 at 0.4 second areconverted into low-resolution preview images, and at the same time,high-resolution images are generated. The generated high-resolutionimages are temporarily stored in the first buffer 209. The number oftemporarily stored high-resolution images is subject to change accordingto a temporary storage space of the first buffer 209. A newhigh-resolution image is temporarily stored as the newesthigh-resolution image and the previously stored high-resolution image isdeleted at intervals of 0.2 second. In case of a camera with multiplebuffers, the image 503 received at 0.2 second is first stored in thefirst buffer 209, and if the image 507 received at 0.4 second is storedlater in the second buffer 219, the first buffer 209 deletes the imagestored at 0.2 second. Thereafter, an image received at 0.6 second isstored in the first buffer 209 and then the image stored in the secondbuffer 219 is deleted. As described above, the number of buffers issubject to change according to user settings.

FIG. 6 shows a process of taking a picture using an image stored in afirst buffer according to an embodiment of the present invention.

Referring to FIG. 6, an image is received through the lens system 201 instep 601. The image is received at the ISP 205 through the image sensor203, and converted into a low-resolution preview image by the ISP 205.That is, the ISP 205 converts the received image into a low-resolutionpreview image according to screen features of the display 207, anddelivers the low-resolution preview image to the display 207. Thedisplay 207 displays in real time the low-resolution preview imageconverted according to its screen features.

In step 603, the ISP 205 generates images at predetermined periods, andtemporarily stores them in the first buffer 209. The image temporarilystored in the first buffer 209 is a high-resolution image, and one ormore high-resolution images may be stored according to a size of astorage space in the first buffer 209. Since new high-resolution imagesshould be sequentially stored with the passage of time, a newhigh-resolution image is stored in an empty space occurring after thefirst stored high-resolution image is deleted, in order to secure astorage space, thereby updating high-resolution images in real time.

In step 605, the controller 213 of the camera determines whether animage capturing signal is received. The image capturing signal isreceived through the key input unit 215. If no image capturing signal isreceived, the controller 213 returns to step 601 and repeats the processof converting the image received through the lens system 201 into apreview image. If an image capturing signal is received, the firstbuffer 209 stores the temporarily stored high-resolution image in thememory 211 according to control of the controller 213 in step 607.Thereafter, in step 609, the temporarily stored high-resolution image isoutput on the display 207.

If the number of high-resolution images temporarily stored in the firstbuffer 209 is one or more, one or more high-resolution images are firstdisplayed on the display 207 so that the user may store only desiredhigh-resolution images in the memory 211. The one or morehigh-resolution images temporarily stored in the first buffer 209 may bedisplayed on the display 207 after they are delivered back to the ISP205 and then converted into low-resolution images according to screenfeatures of the display 207.

In case of a camera with the first buffer 209 and the second buffer 219,if a new high-resolution image is stored in the first buffer 209 andthen a high-resolution image generated in the next period is stored inthe second buffer 219, the first buffer 209 deletes the previouslystored high-resolution. If a high-resolution image is stored in thefirst buffer 209 in a period following the next period, thehigh-resolution image stored in the second buffer 219 is deleted.

As is apparent from the foregoing description, exemplary embodiments ofthe present invention display one or more high-resolution imagestemporarily stored in the first buffer on a display in various mannersso that a user may select only desired images and store only theselected images in a memory separately, thereby securing a storagespace.

While the invention has been shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims and their equivalents.

What is claimed is:
 1. A method for capturing an image using an imagestored in a camera, the method comprising: receiving images from animage sensor; converting, at each one of a plurality of first timepoints separated by a first predetermined interval, one of the receivedimages corresponding to the one of the first time points into a previewimage, and displaying each preview image on a display; generating, ateach one of a plurality of second time points separated by a secondpredetermined interval having a different length than the firstpredetermined interval, a high-resolution image from one of the receivedimages corresponding to the one of the second time points, eachhigh-resolution image having a higher resolution than each previewimage; providing the generated high-resolution images sequentially to afirst buffer and a second buffer; temporarily storing the sequentiallyprovided high-resolution images sequentially in the first buffer and thesecond buffer; and storing, in a separate area of memory, in response toan input of an image capturing signal, a high-resolution imagesequentially temporarily stored in the first buffer and the secondbuffer.
 2. The method of claim 1, wherein the second predeterminedinterval is a longer length of time than the first predeterminedinterval.
 3. The method of claim 1, wherein the first buffer temporarilystores a plurality of the provided high-resolution imagessimultaneously.
 4. The method of claim 3, further comprising: displayingthe plurality of the high-resolution images sequentially temporarilystored in the first buffer and the second buffer; and selecting thehigh-resolution image among the displayed plurality of thehigh-resolution images in response to the input of the image capturingsignal.
 5. The method of claim 4, wherein storing includes storing theselected high-resolution image in the separate storage space.
 6. Themethod of claim 1, wherein temporarily storing the sequentially providedhigh-resolution image in the first buffer and the second buffercomprises: temporarily storing the sequentially provided high-resolutionimage in the first buffer; temporarily storing the sequentially providedhigh-resolution image in the second buffer; deleting the sequentiallyprovided high-resolution image previously stored in the first buffer andtemporarily storing the sequentially provided high-resolution image inthe first buffer; and deleting the sequentially provided high-resolutionimage previously stored in the second buffer and temporarily storing thesequentially provided high-resolution images in the second buffer.
 7. Anapparatus for capturing an image using an image stored in a camera, theapparatus comprising: a lens system for optically receiving images; animage signal processor for converting, at each one of a plurality offirst time points separated by a first predetermined interval, one ofthe received images corresponding to the one of the first time pointsinto a preview image, generating, at each one of a plurality of secondtime points separated by a second predetermined interval having adifferent length than the first predetermined interval, ahigh-resolution image from one of the received images corresponding tothe one of the second time points, each high-resolution image having ahigher resolution than each preview image, and providing generated thehigh-resolution images sequentially to a first buffer and a secondbuffer; the first buffer for temporarily storing, for each of thehigh-resolution images provided to the first buffer, the sequentiallyprovided high-resolution image; the second buffer for temporarilystoring, for each of the high-resolution images provided to the secondbuffer, the sequentially provided high-resolution image; a display fordisplaying each of the preview images; and a controller for controllingstoring, in response to an input of an image capturing signal, ahigh-resolution image sequentially temporarily stored in the firstbuffer and the second buffer into a separate area of memory.
 8. Theapparatus of claim 7, wherein the second predetermined interval is alonger length of time than the first predetermined interval.
 9. Theapparatus of claim 7, wherein the first buffer temporarily stores aplurality of the provided high-resolution images simultaneously.
 10. Theapparatus of claim 9, wherein the display displays the plurality ofhigh-resolution images and the controller controls storing thetemporarily stored high-resolution image into the separate memory, inresponse to the input of the image capturing signal.